Micro-electromechanical system (MEMS) devices are very small and fragile. They need to be protected from physical harm and contamination. Some MEMS devices require a special environment, such as a gas or liquid fluid, in which to operate. Prior attempts to provide such protection involve the use of a cover, such as a window or plate fixed over the MEMS device to protect it. Such windows or plates may be fixed on an annular ring of a polymer extending above and around the MEMS device. It may be difficult to form the ring with desired materials due to thermal budget constraints. The ring may also need to be formed in such a manner to facilitate sufficient sealing of the cover.